2.1.20—Ecosystems as open systems
- Syllabus
- First assessment 2026
- Objective
- 2.1.20
- Level
- SL
An Ecosystem Is Open to Matter and Energy
An ecosystem links a community with its abiotic environment, and energy and matter cross its boundary.
Sunlight enters, heat leaves, and water, gases, nutrients and organisms can cross. Drawing a boundary helps analysis but does not isolate the ecosystem from neighbours.
A forest receives rain and sunlight, exports heat and dissolved nutrients, and exchanges animals with surrounding habitat.
No. Matter can cycle internally and also enter or leave the ecosystem.
‘Cycles’ does not mean the ecosystem is closed.